Thin display device

ABSTRACT

A position adjusting mechanism, a rotation-axle bearing mechanism, and a rotation-speed reduction mechanism for a flat display apparatus. The rotation-speed reduction mechanism comprises a position adjusting mechanism that includes one or more means for securely attaching a stand and a main body unit of the apparatus to one another, and a position adjusting means for adjusting the mounting position of the stand and main body unit. The rotation-axle bearing mechanism comprises a radial bearing and a thrust bearing for supporting a rotation axle between a display screen unit and the stand. The rotation-speed reduction mechanism reduces the speed of rotation between the display screen unit and the stand upon application of a rotation load exceeding a certain level.

TECHNICAL FIELD

The present invention relates to a rotation adjusting mechanism for astand-type flat display apparatus. In particular, it relates to aposition adjusting mechanism for rotating a display screen unit of astand-type flat display apparatus equipped with a single-axle typerotation mechanism while maintaining the horizontal position of thedisplay screen unit.

The invention further relates to a stand rotation mechanism for a flatdisplay apparatus, particularly to a rotation-axle bearing mechanism forallowing for the rotation of a display unit of a flat display apparatusin a mounting position such that the center of the weight of the mainbody of the flat display apparatus does not correspond to the centralaxis of the stand.

The invention further relates to a stand rotation mechanism for a flatdisplay apparatus, particularly to a rotation-speed reduction (or torquelimiter) mechanism in the rotation mechanism for reducing the inputrotation speed of a rotation motor or the like and then supplying anoutput to gears or the like, and also for protecting the apparatus fromexcessive rotation load.

BACKGROUND ART

In recent years, stand-type flat display apparatuses with a displayscreen comprising an LCD (liquid crystal display), a plasma display, oran EL (electronic luminescence) display, are becoming increasinglycommon. In particular, there is an increasing need for large-sizedstand-type flat display apparatuses equipped with a display screen sizeof 30 inches or larger. A variety of such products have been developedfor household or business purposes.

In these stand-type flat display apparatuses, a display screen unitincludes an LCD, plasma or EL display, and a main body unit includes anamplifier unit, power supply, drive circuit and other devices. Thedisplay screen unit and the main body unit are typically supported by astand including a leg extending horizontally such that the displayscreen unit stands substantially vertically with respect to the floor.The stand further includes a rotation mechanism by which the main bodyunit can be axially supported in a freely rotatable manner.

FIG. 1 shows an elevational view of an example of the above-describedstand-type flat display apparatus. A flat display apparatus 100 is aconsole-type flat display apparatus including a display screen unit 110,a main body unit 120, and a stand 130. The term “console type” refers tothe type of flat display apparatus in which the main body unit 120 iscomposed of a control unit 121 including a power supply, a drive circuitand a control circuit and an amplifier unit 122, and in which the mainbody unit 120 is integrated with the display screen unit 110.

The display screen unit 110 includes a display screen 111 such as anLCD, plasma or EL display. The main body unit 120 includes the controlunit 121 and amplifier unit 122. The main body unit 120 is integratedwith the display screen unit 110 and axially supported by the stand 130.The stand 130 is comprised of a stand support column 131 and a standbase 132. The stand support column 131 has a rotation mechanism by whichthe main body unit 120 can be supported in a freely rotatable manner.

(1) As an example of the rotation mechanism for the above-describedstand-type flat display apparatus, JP Patent Publication (Kokai) No.08-331485 A (1996) discloses a rotation mechanism for television sets.In this rotation mechanism, sliding rollers 7 are disposed at ends ofeach side of the bottom of the television main body unit for supportingthe weight thereof and allowing the same to be rolled. The slidingrollers 7 are adapted to roll on the upper surface of a television stand13, thus allowing the television main body unit to be rotated.

It is difficult, however, to apply this television rotation mechanism tothe rotation mechanism for the stand-type flat display apparatus. Thisis due to the fact that the aforementioned mechanism, in which thetelevision main body unit and the rollers are adapted to roll, requirescertain width and depth in the television main body unit and thetelevision stand. Further, it creates a gap between the television mainbody unit and the television stand and thus exposes the inside of thetelevision stand as the television main body unit is rotated.

(2) Referring to FIG. 1, the display screen unit 110 includes thedisplay screen 111 such as an LCD, plasma or EL display. The main bodyunit 120 includes the control unit 121 and amplifier unit 122. The mainbody unit 120 is integrated with the display screen unit 110 and axiallysupported by the stand 130. The stand 130 is composed of the standsupport column 131 and stand base 132. The stand support column 131 hasa rotation mechanism by which the main body unit 120 can be supported ina freely rotatable manner.

As a conventional example of this rotation mechanism, JP PatentPublication (Kokai) No. 10-32771 shows a rotation mechanism in which asupport column 7 supporting a display 3 and a rotation platform 2 aresupported on a base 1. A thrust bearing 8 is disposed between the base 1and the rotation platform 2 in order to allow the display 3 to berotated.

If this rotation mechanism were to be applied to the stand-type flatdisplay apparatus, a structure would have to be adopted such that thedisplay screen unit and the main body unit are axially supported by thesupport column of the stand in a freely rotatable manner.

(3) In the stand-type flat display apparatus as shown in FIG. 1, therotation mechanism in the stand 130 is typically equipped with a drivemotor, for example, to allow for an automatic rotation of the displayscreen unit 110 and the main body unit 120.

In this type of automatic rotation mechanism, a means is provided toreduce the rotation output of the drive motor at a certain reductionratio. Specifically, a certain amount of load is put on the rotationaxle being rotated so that the rotation can come to a stop when thedrive motor is stopped. By appropriately selecting the reduction ratio,the automatic rotation speed can be controlled. For example, a winchmechanism is commonly provided in the worm unit connected to the drivemotor.

Similar rotation-speed reduction mechanisms in conventional displayapparatuses are disclosed in JP Utility Model Publication (Kokai) No.63-61884 A (1988) and JP Utility Model Publication (Kokai) No. 64-31246U (1989).

The former, JP U.M. Kokai 63-61884, discloses a rotating cabinet inwhich a cabinet main body unit is placed on a pedestal in a freelyrotatable manner. A bevel gear and an output gear are adapted to beengaged due to the weight of the cabinet main body unit, and a reducinggear train is arranged in a vertical direction and is driven.

The latter, JP Utility Model 64-31246, discloses a turning mechanismcomprising a gear that receives the rotation of a gear mechanism, abevel gear adapted to resiliently engage the gear on the axis side, anda clutch mounted on an upper platform in such a manner as to engage thebevel gear. In this turning mechanism, the gear mechanism and the motorare protected from damage in the event of an excessive load torque.

DISCLOSURE OF THE INVENTION

Regarding the Position Adjusting Mechanism of the Flat Display Apparatus

As the stand-type flat display apparatus becomes larger in size, thedisplay screen correspondingly becomes larger and thus a considerableweight must be supported by the stand. Conventionally, a large-sizeddisplay screen is supported by two stands via the left and right edgesof the display screen. Alternatively, a trapezoidal stand is used toincrease the area of contact between the stand and the display screen.There is, however, a demand for allowing a large-sized display screen tobe supported with a single stand.

At the same time, the single-axle stand must be capable of rotating thedisplay screen unit in a horizontal manner. In the case of a large-sizedstand-type flat display apparatus, in particular, even a slightinclination in a horizontal direction results in a large difference inheight between the left and right edges of the wide display screen unit,making it appear to the user as if the display is greatly inclinedhorizontally. For example, it is known that in the case of a certainlarge-sized LCD television, the user can recognize a tilting if there isan inclination of 20′ (approximately ⅓ degrees) or more horizontally.

A stand-type flat display apparatus is typically designed such that itsmain body unit can be rotated relative to the stand either manually orautomatically. The horizontal position of the main body unit must bestabilized such that it does not swing either left or right duringrotation.

The horizontal position can be easily adjusted by supporting the displayunit with two stands or supporting axles. However, if the display unitis to be supported on the stand with a single supporting axle, it isinevitable in reality that slight variations are produced in the size ofthe individual components or that slight errors are introduced into thepositioning of individual components during assembly, no matter howprecisely the horizontal positioning of the main body unit is designed.Thus, it is extremely difficult to manufacture a stand-type flat displayapparatus in which the horizontal positioning of the main body unit isprecisely maintained according to design.

Thus, it is an object of the invention to provide a position adjustingmechanism for a stand-type flat display apparatus equipped with asingle-axle rotation mechanism, whereby the display screen unit can beretained horizontally.

Regarding the Rotation-Axle Bearing Mechanism in the Flat DisplayApparatus

The stand-type flat display apparatus is quite heavy due to thematerials such as glass used in the entire liquid crystal panel on thedisplay screen unit. Further, as the LCD panel portion and the casingare constructed in an integral manner, the weight of the main body isheavier the larger the size of the display apparatus is. In addition, inthe case of a stand for a flat display apparatus, there is the problemthat the flat display apparatus cannot be made to look thinner unlessthe stand unit is made thinner than the main body unit when looked atsideways.

For these reasons, if the main body display unit is attached towards thefront of the screen farther than the center of axle of the stand unit,the center of gravity of the display screen unit and main body unit isinclined greatly towards the front. As a result, the center of gravityof the display screen unit and main body unit is greatly displaced fromthe center of rotation of the stand.

Particularly, when the display screen unit of the flat display apparatusis positioned forwardly of the periphery of the rotation mechanism, thecenter of gravity of the display screen unit would be located forwardlyof the periphery of the rotation mechanism, resulting in a greaterdisplacement between the center of rotation of the stand and the centerof gravity.

If the display screen unit and the main body unit are rotated in thiscondition, a load would be put on the bearing of the rotation mechanismin an irregular manner, thus interfering with a smooth rotation of thedisplay screen unit and the main body unit. While in the aforementionedrotation mechanism of JP 08-331485 (FIG. 6) a sufficient stability isprovided by the thrust bearing in the direction of gravity, there is noconsideration given to the displacement of the center of gravity of thedisplay screen unit and main body unit as they rotate. If such arotation mechanism is employed in the stand-type flat display apparatus,the axle and bearing of the rotation mechanism would wobble vertically,thus preventing a smooth rotation of the display screen unit and mainbody unit.

Thus, it is an object of the invention to provide a rotation mechanismfor a stand-type flat display apparatus in which the center of gravityof the display screen unit and main body unit is distanced from thecenter of rotation of the rotation mechanism of the stand, whereby asmooth and stable rotation can be ensured.

Regarding the Rotation-Speed Reduction Mechanism in the Flat DisplayApparatus

When the stand-type flat display apparatus shown in FIG. 1 is actuallyrotated automatically, the rotation could be impeded by a variety ofreasons. For example, if the display screen unit 110 and the main bodyunit 120 come into contact with an obstacle, they might not be able torotate further. It is also possible that the user might try to terminatethe rotation by hand, or that he or she might attempt to start rotatingthe display screen unit 110 and the main body unit 120 with an excessiveforce.

If such an abnormal load is applied to the rotation mechanism, anexcessive load would be put on the gear and motor and other components,particularly during automatic rotation, possibly causing damage to suchcomponents.

Thus, it is another object of the invention to provide a stand-type flatdisplay apparatus equipped with a rotation mechanism in which thecomponents of the rotation mechanism are protected from a potentiallyexcessive rotation load or abnormal rotation load.

Regarding the Position Adjusting Mechanism of the Flat Display Apparatus

The present invention provides an apparatus comprising a main body unitand a stand unit having a single-axle rotation unit for supporting themain body unit, the apparatus further comprising means for adjusting theinclination of the horizontal position of the main body unit where thestand unit and the main body unit are connected to one another.

The present invention further provides a flat display apparatuscomprising a main body unit with a display screen and a stand unit witha single rotation axle for supporting the main body unit, the apparatusfurther comprising means for adjusting the inclination of the horizontalposition of the main body unit where the stand unit and the main bodyunit are connected.

Preferably the flat display apparatus further comprises means fortemporarily securing the stand unit and the main body unit and means forfully securing the stand unit and the main body unit where the standunit and the main body unit are connected, wherein the stand unit andthe main body unit are temporarily secure to one another and then theinclination of the main body unit is adjusted by the inclinationadjusting means, before the stand unit and the main body unit are fullysecured to one another.

According to the present invention, the inclination-adjusting meanscomprises an eccentric member disposed where the stand unit and the mainbody unit are connected.

The present invention further provides a flat display apparatuscomprising a main body unit with a display screen and a stand unit witha single rotation axle for supporting the main body unit, the apparatusfurther comprising: connecting means for connecting the stand unit andthe main body unit, wherein the connecting means comprises a securingmeans for securing the stand unit and the main body unit to one another,and inclination adjusting means for adjusting the inclination of thehorizontal position of the main body unit.

According to the present invention, the connecting means furthercomprises a positioning pin for positioning the stand unit and the mainbody unit.

The present invention further provides a flat display apparatuscomprising a main body unit with a display screen and a stand unit witha single rotation axle for supporting the main body unit, the apparatusfurther comprising a connecting member for connecting the stand unit andthe main body unit, the connecting member comprising: a securing openingfor allowing the stand unit and the main body unit to be secured to oneanother with a screw; and an inclination adjusting opening for adjustingthe inclination of the horizontal position of the main body unit,wherein the inclination of the main body unit can be adjusted byinserting an eccentric cam into the inclination adjusting opening androtating the eccentric cam.

Regarding the Rotation Axle Bearing Mechanism of the Flat DisplayApparatus

The present invention provides a main body unit with a display screen, astand unit, and a rotation mechanism for rotating the main body unithorizontally with respect to the stand unit, wherein the rotationmechanism comprises a plurality of kinds of bearings for supporting arotation axle.

According to the present invention, the plurality of kinds of bearingscomprise a combination of a radial bearing and a thrust bearing.

According to the present invention, the plurality of kinds of bearingsare mounted towards the top and bottom of the rotation axle.

According to the present invention, the center of gravity of the mainbody unit is located outside a reference rotation periphery defined bythe thrust bearing.

The present invention further provides a flat display apparatuscomprising a rotation mechanism made up of an upper unit and a lowerunit, wherein the lower unit has a single rotation axle secured thereto,and the upper unit has a plurality of kinds of radial bearingssupporting the rotation axle, the upper and lower units being capable ofrotating relative to one another.

According to the present invention, a stopper is disposed near the tipof the rotation axle, the stopper being secured in place while applyinga certain force in the axial direction.

Regarding the Rotation Speed Reduction Mechanism of the Flat DisplayApparatus

The present invention provides a flat display apparatus comprising amain body unit with a display screen, a stand unit, and a rotationmechanism for rotating the main body unit horizontally with respect tothe stand unit, wherein the rotation mechanism is adapted to reduce thespeed of rotation upon application of a rotation load exceeding acertain level.

According to the present invention, the rotation mechanism comprises twoore more gears and a clutch mechanism for reducing the speed of rotationbetween the individual gears upon application of a rotation loadexceeding a certain level.

According to the present invention, the rotation mechanism comprises twoor more gears, of which two or more gears are torque-limiting gears thatare adapted to reduce the speed of rotation upon application of arotation load exceeding a certain level.

According to the present invention, the torque-limiting gears include anupper gear and a lower gear, wherein the upper and lower gears areadapted to frictionally slide upon one another upon application of arotation load exceeding a certain level.

According to the present invention, the torque-limiting gears include agear base, an upper gear secured to the gear base, and a lower geardisposed between the gear base and the upper gear, wherein the gear basehas a friction member disposed on the surface thereof facing the lowergear, and wherein a resilient member is disposed between the upper andlower gears, the resilient member being adapted to press the lower gearagainst the friction member such that the lower gear and the gear basefrictionally slide upon one another.

According to the present invention, the rotation mechanism includes adrive motor and is capable of automatic rotation.

Preferably the flat display apparatus further comprises means forreceiving remote operation, wherein the rotation of the rotationmechanism is controlled by remote operation.

According to the present invention, the rotation mechanism includes aposition sensor and is capable of recognizing its own rotation position.

According to the present invention, the rotation mechanism is adapted toreduce the speed of rotation between the motor and the gears or betweenthe gears, the rotation mechanism further comprising a torque-limitinggear, wherein the speed of rotation is reduced as an upper gear and alower gear of the torque-limiting gear frictionally slide upon oneanother.

According to the present invention, the torque-limiting gear includes agear base to which the upper gear is secured, and wherein the lower gearis disposed between the gear base and the upper gear, wherein the gearbase has a friction member disposed on the surface thereof facing thelower gear, and a resilient member is disposed between the upper andlower gears, the resilient member being adapted to press the lower gearagainst the friction member such that the lower gear and the gear basefrictionally slide upon one another.

According to the present invention, wherein the display screen includesa liquid crystal display, a plasma display, or an EL display.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevational view of an example of a stand-type flatdisplay apparatus.

FIG. 2 shows the structure of a frame supporting a display screen unitand a main body unit of the stand-type flat display apparatus shown inFIG. 1.

FIG. 3 is an enlarged rear view of a rotation unit and a mounting anglethat are used in a position adjusting mechanism of the stand-type flatdisplay apparatus according to a first embodiment of the invention.

FIG. 4 is an enlarged side view of the rotation unit and the mountingangle that are used in the position adjusting mechanism of thestand-type flat display apparatus according to the first embodiment.

FIG. 5 is an enlarged top view of the rotation unit and the mountingangle that are used in the position adjusting mechanism of thestand-type flat display apparatus according to the first embodiment.

FIG. 6 is a top view of the rotation unit, mounting angle and analuminum frame as assembled in the position adjusting mechanism of thestand-type flat display apparatus according to the first embodiment.

FIG. 7 is a rear view of the rotation unit and the mounting angle thatare used in the position adjusting mechanism, similar to FIG. 3, but inwhich an eccentric cam is inserted in a position adjusting opening.

FIG. 8 shows a rotation-axle bearing mechanism in a stand-type flatdisplay apparatus according to a second embodiment of the invention.

FIG. 9 shows a front elevational cross-section of the rotation unit usedin the rotation-axle bearing mechanism in the stand-type flat displayapparatus according to the second embodiment.

FIG. 10 shows a lateral cross-section of the rotation unit used in therotation-axle bearing mechanism in the stand-type flat display apparatusaccording to the second embodiment.

FIG. 11 is a bottom view of an upper unit of the rotation unit used inthe rotation-axle bearing mechanism in the stand-type flat displayapparatus according to the second embodiment.

FIG. 12 is a top view of an upper unit of the rotation unit used in therotation-axle bearing mechanism in the stand-type flat display apparatusaccording to the second embodiment.

FIG. 13 is a plan view showing the internal structure of a rotationspeed reduction mechanism of a stand-type flat display apparatusaccording to a third embodiment of the invention.

FIG. 14 shows a lateral cross-section of the rotation speed reductionmechanism of a stand-type flat display apparatus according to a thirdembodiment of the invention, showing the internal structure thereof.

FIG. 15 is an enlarged cross-section of a torque-limiting gear includedin the rotation speed reduction mechanism of a stand-type flat displayapparatus according to a third embodiment of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The best modes for carrying out the invention will be hereafterdescribed by referring to the attached drawings.

FIGS. 1 to 15 show various embodiments of the invention wherein likeelements with basically identical structure and function are numberedalike.

FIG. 1 shows a frontal elevation of an example of the stand-type flatdisplay apparatus according to the invention. FIG. 1(a) shows an examplewhere a display screen unit 110 and a main body unit 120 are supportedby a stand unit 130. Another example shown in FIG. 1(b) is similar tothe example of FIG. 1(a) except that the leg of the stand unit 130 ismade longer. In another example shown in FIG. 1(c), the main body unit120 is mounted behind the display screen unit 110 in an integral manner.

FIG. 2 shows the frame structure for supporting the display screen unitand main body unit of the stand-type flat display apparatus shown inFIG. 1 and the rotation mechanism for allowing the rotation of thedisplay screen unit and main body unit thereof. As shown in FIG. 2, inthis stand-type flat display apparatus, an aluminum frame 230 issupported via a mounting angle 220 by a rotation unit 210 of the standin a freely rotatable manner.

FIGS. 2(a) and (b) show examples corresponding to FIGS. 1(a) and (b).

First Embodiment: Flat Display Apparatus Equipped with PositionAdjusting Mechanism

The position adjusting mechanism of the flat display apparatus accordingto the present embodiment is used at a stand-supported portion of thestand-type flat display apparatus shown in FIGS. 1 and 2. By theposition adjusting mechanism, the rotation unit 210 and the mountingangle 220 securely attached thereto are positioned and secured to thealuminum frame 230.

FIGS. 3, 4 and 5 are rear, side view and top views, respectively, of therotation unit 210 and mounting angle 220 of the stand shown in FIG. 2.FIGS. 3(a) and (b) show examples corresponding to FIGS. 1(a) and (b),respectively.

Referring to FIGS. 3 to 5, the mounting angle 220 includes positioningpins 310, fixing openings 321 to 326, and position adjusting openings331 to 332. The positioning pins 310 are adapted to engage with bosses231 (see FIG. 2) extended from a front panel (made of plastic) via thealuminum frame 230, such that the mounting angle 220 can be roughlypositioned when attached to the aluminum frame 230. The fixing openings321 to 326 and the position adjusting openings 331 and 332 are adaptedto accommodate screws for fine-adjusting the mounting positions of themounting angle 220 and the aluminum frame 230, as will be describedlater.

Hereafter the mounting of the rotation unit 210, the mounting angle 220and the aluminum frame 230 will be described. FIG. 6 shows a top view ofthe rotation unit 210, the mounting angle 220 and the aluminum frame 230as assembled.

Referring to FIG. 6(a) and FIG. 7, initially, each positioning pin 310on the mounting angle 220 is inserted into an opening provided in eachboss 231 extending from the (plastic) front panel through the aluminumframe 230, thus determining the mounting positions. Then, the aluminumframe 230 is fastened with a screw. The aluminum frame 230 is fixed withscrew only to such an extent that the mounting angle 220 can be slightlyrotated relative to the aluminum frame 230 about the center of the screwin the fixing opening 321. This is followed by a temporary fixing of theother fixing openings 322 to 326. The temporary fixing is carried outwith such a torque that the main body unit of the flat display apparatusis not inclined by its own weight.

In the present embodiment, the mounting position of the rotation unit210 and the aluminum frame 230 may preferably be modified as shown inFIG. 6(b). Such a modification can be effected by changing the design ofthe angle 220 or the positioning pin 310 in an appropriate manner.Further, an L-shaped mounting member may be used, as shown in FIG. 6(c).

Then, the mounting positions of the rotation unit 210, the mountingangle 220 and the aluminum frame 230 are finely adjusted. FIG. 7 shows arear view of the rotation unit and mounting angle, similar to FIG. 3. InFIG. 7, however, an eccentric cam 341 is inserted into the positionadjusting opening 331. FIGS. 7(a) and (b) show examples corresponding toFIG. 1(a) and (b).

In the present embodiment, the eccentric cam 341 has an oval-shapedscrew head. Thus, as the eccentric cam 341 is rotated, the diameter ofthe screw head in a vertical direction varies. In FIG. 7, as theeccentric cam 341 is rotated to the right, the screw head will haveincreasingly larger diameter in the vertical direction, so that theupper inner wall of the position adjusting opening 331 will be pushedupward by the eccentricity cam 341.

If the mounting angle 220 should be adjusted in the opposite direction,the eccentric cam 341 may be inserted into the position adjustingopening 332. By rotating the eccentric cam 341 to the left, the lowerinner wall of the position adjusting opening 332 can be pushed downward.

The mounting angle is thus allowed to rotate slightly about the axis ofthe screw in the fixing opening 321. Accordingly, by finely adjustingthe mounting positions of the rotation unit 210, mounting angle 220 andaluminum frame 230 while rotating the eccentric cam 341, the position ofthe display screen unit and main body unit of the flat display apparatuscan be fine-adjusted to be horizontal.

After the fine adjustment is over, the fixing openings 322 to 326 thathave been temporarily fastened are fully fastened with the screw, thusfully fixing the rotation unit 210, mounting angle 220 and aluminumframe 230 in place.

The shape of the eccentric cam 341 may be formed in various manners aslong as it is asymmetric with respect to the rotation center. Forexample, the shape may be either oval or eccentric circle, and yet thecam with such a shape can still function as the above-described positionadjusting mechanism.

The mounting positions of the fixing openings 321 to 326 and theposition adjusting openings 331 and 332 on the mounting angle 220 shownin FIGS. 3 and 7 are merely exemplary and various other examples arepossible.

For example, while in the above description the mounting position of thedisplay screen unit and the main body unit is finely adjusted bymanually rotating the eccentric cam 341, the fine adjustment may becarried out automatically. In such a case, an appropriate electricposition adjusting means may be provided.

The position adjusting mechanism in the stand-supported portion of thestand-type flat display apparatus as described above can be applied toall kinds of equipment supported by a stand.

Second Embodiment: Flat Display Apparatus Equipped with a Rotation-AxleBearing Mechanism

The rotation-axle bearing mechanism of the flat display apparatusaccording to the present embodiment is used in the stand-supportedportion of the stand-type flat display apparatus shown in FIGS. 1 and 2.The rotation-axle bearing mechanism is built inside the rotation unit210.

FIG. 8 shows the rotation unit 210 comprising the rotation mechanismaccording to the present embodiment. The rotation unit 210 is comprisedof an upper unit 810 and a lower unit 820. The upper and lower units areadapted to rotate relative to one another with a predetermined rotationtorque. The upper unit 810 is secured to the aluminum frame 230 via themounting angle 220, and the lower unit 820 is secured to the stand base132.

FIG. 9 shows a cross-sectional front elevation of the rotation unit 210.FIG. 10 shows a cross-sectional side elevation of the same unit. FIG. 11shows a bottom view of the upper unit 810 of the rotation mechanism ofthe present embodiment. FIG. 12 shows a top view of the lower unit 820of the rotation mechanism of the embodiment.

In the rotation mechanism shown in FIGS. 9 and 10, the lower unit 820has a rotation axle 910 secured thereto. The upper unit 810 includes anupper ball bearing 920 and a lower ball bearing 930 that constituteradial bearings for the rotation axle 910. The lower end of the rotationaxle 910 is fastened to the lower unit 820 with a bolt 940. The upperend of the rotation axle 910 is anchored to a bearing portion of theupper unit 810 via a washer 950.

The rotation mechanism of the present embodiment further includes aplurality of rollers 960 arranged between the upper and lower unitsalong a circumference that is coaxial with the rotation axle 910 atpredetermined intervals. Each of the rollers 960 are adapted to roll incontact with the upper surface of the lower unit 820, thus functioningas a thrust bearing.

Thus, the rotation mechanism of the present embodiment includes twotypes of bearings, namely the radial bearing consisting of the upperball bearing 920 and the lower ball bearing 930, and the thrust bearingconsisting of the rollers 960. The rotation mechanism with such astructure receives a thrust load mainly with the thrust bearing whilereceiving a radial load mainly with the radial bearing, thereby allowingfor a smooth and stable rotation even if the center of gravity is notlocated on the rotation axis, as in the case of a flat displayapparatus.

This structure consisting of a thrust bearing and a radial bearing isparticularly effective when the center of gravity of the flat displayapparatus is located outside the reference rotation circumference(referring to the circumference on which the center of each roller 960in the radius direction is positioned; namely, circumference 961 in FIG.11) of the radial bearing. This is because of the fact that such adisplacement of the center of gravity with respect to the axle thatcannot be covered by the thrust bearing can only be covered by theradial bearing, thus providing a smooth rotation.

Thus, by employing the above-described rotation mechanism in the flatdisplay apparatus, a smooth rotation can be obtained in the flat displayapparatus even when the display screen unit is disposed forwards outsidethe periphery of the thrust bearing.

In accordance with the present embodiment, a stopper (or collar) 970 isprovided in an upper part of the upper unit 810 for retaining therotation axle 910. The stopper 970 is fastened to the rotation axle 910with a screw (not shown) provided on the side of the collar after therotation axle 910 is secured in place by the bolt 940, while applying acertain pressure on the stopper 970. Thereafter, the washer 950 isattached to the upper end of the axle in order to prevent the droppingof the stopper 970. Specifically, the stopper 970 is fastened with screwwhile pressuring the stopper with a predetermined weight (about 10 kg)(which is referred to as a “fixed position pressurization”). As aresult, the wobbling of the rotation axle in the vertical direction canbe eliminated, thus providing a smoother and more stable rotation.

The foregoing description of the rotation-axle bearing mechanism used inthe stand-supported portion of the stand-type flat display apparatus ismerely exemplary. Thus, various known techniques can be used in supportof the structures of the radial bearing and thrust bearing in therotation-axle bearing mechanism.

Third Embodiment: Flat Display Apparatus Equipped with a Rotation-SpeedReduction Mechanism

The rotation-speed reduction mechanism of the flat display apparatusaccording to the present embodiment is used at the stand-supportedportion of the stand-type flat display apparatus shown in FIGS. 1 and 2.The rotation-speed reduction mechanism is build inside the rotation unit210.

FIG. 13 shows a cross section of the rotation unit 210, in which therotation mechanism used in the stand-type flat display apparatus of thepresent embodiment is included. In FIG. 13, the rotation mechanismincludes a drive motor 1310, a worm 1311, a first gear 1320, a secondgear 1330, a third gear 1340 and a position sensor 1350. The drive motor1310 is an electric motor. The worm 1311, first gear 1320, second gear1330 and third gear 1340 are made of plastic, for example.

FIG. 14 shows a lateral cross section of the rotation mechanism. As willbe seen from the figure, the worm 1311 engages with a lower gear of thefirst gear 1320. An upper gear of the first gear 1320 engages with anupper gear of the second gear 1330. A lower gear of the second gear 1330engages with an upper gear of the third gear 1340. A lower gear of thethird gear 1340 is used as an output gear.

In the rotation mechanism employed in the stand-type flat displayapparatus of the present embodiment, the first gear 1320 is adapted tofunction as a torque-limiting gear for reducing the speed of rotation.The structure of the first gear 1320 is shown in detail in an enlargedcross-section of FIG. 15. As shown FIG. 15, the first gear 1320 is madeup of a gear base 1321, an upper gear 1322, a lower gear 1323, a spring1324, and a friction member 1325.

The upper gear 1322 is fixed to a gear base 1321 and thus integratedtherewith. The lower gear 1323 is mounted on an axle portion of the gearbase 1321 in a freely rotatable manner. The spring 1324 is made ofconventional metal, for example, and it is adapted to put pressure onthe upper gear 1322 and the lower gear 1323 at all times. The frictionmember 1325 is made of felt, for example, and is fixedly attached to thegear base 1321 by glue, for example, and thus integrated therewith. Thefriction member 1325 produces a predetermined level of friction betweenthe gear base 1321 and the lower gear 1323.

The thus-structured rotation mechanism in the stand-type flat displayapparatus according to the present embodiment operates as follows.

Referring to FIG. 13, as the drive motor 1310 is driven, the worm 1311rotates. The rotation of the worm 1311 is transmitted to the first gear1320, second gear 1330, and third gear 1340 successively, and thenoutputted from the lower gear of the third gear 1340.

It is now assumed that a rotation load has been applied to a stand-typeflat television set according to the present embodiment during itsautomatic rotation in a direction opposite to the direction of automaticrotation, due to an obstacle or someone's hand. The rotation load issuccessively transmitted from the lower gear of the third gear 1340 tothe second gear 1330 and then to the first gear 1320. If the rotationload put on the first gear 1320, which is a torque-limiting gear, isgreater than a predetermined level, a clutch mechanism in the first gear1320 is activated to reduce the rotation load, as will be describedbelow.

Referring to FIG. 15, the gear base 1321 and lower gear 1323 of thefirst gear 1320 are adapted to frictionally slide on one another via thefriction member 1325. When the drive motor 1310 is being driven and therotation mechanism is normally executing an automatic rotation, a staticfrictional force is produced between the friction member 1325 and thelower gear 1323. As a result, the rotation of the worm 1311 istransmitted to the gear base 1321 and the upper gear 1322 without loss.

However, if a rotation load in excess of the static frictional forcebetween the friction member 1325 and the lower gear 1323 is applied, thelower gear 1323 rotates while frictionally sliding on the frictionmember 1325. As a result, the rotation load transmitted from the lowergear of the third gear 1340 is reduced between the friction member 1325and the lower gear 1323. Thus, in this mechanism, no load in excess ofthe kinetic friction between the friction member 1325 and the lower gear1323 would be transmitted to the drive motor 1310 no matter how muchrotation load is put on the third gear from the outside.

Accordingly, the rotation drive force produced by the drive motor 1310is never on a collision course with an excessive rotation force appliedexternally to the rotation mechanism during automatic rotation. Thus,the individual components of the rotation mechanism are spared of anyexcessive load.

It is possible that an excessive rotation load is applied manually bythe user when the rotation unit is at rest. In such a case too, therotation load applied via the third gear 1340 can be reduced by thefirst gear 1320, so that the individual components are not subject tothe excessive load.

In the rotation mechanism in the stand-type flat display apparatus ofthe present embodiment, the coefficient of friction between the gearbase 1321 and lower gear 1323 of the first gear 1320 can be adjusted byadjusting the force of the spring 1324. Alternatively, the frictionalcoefficient can be obviously adjusted by selecting the material of thefriction member 1325.

The stand-type flat display apparatus according to the presentembodiment is further equipped with a position sensor 1350 at therotation mechanism portion. The position sensor 1350 is used to detectthe current rotation position by monitoring the inner wall of therotation unit.

Preferably, when the stand-type flat display apparatus of the presentembodiment is actually installed at home, for example, the rotationmechanism should have a rotation torque such that the display screenunit would not be rotated by a blow of wind but can be rotated when theuser applies a gentle rotational pressure. For example, the frictionmember 1325 and the lower gear 1323 should preferably start sliding onone another upon application of a load of approximately 1.5 kg.

While the rotation-speed reduction mechanism in the stand-supportedportion of the stand-type flat display apparatus has been described byway of an embodiment, various modifications or variations can be addedto the embodiment. For example, the torque-limiting gear does notnecessarily have to be the first gear 1320, and so either the second orthe third gear may be adapted to function as the torque-limiting gear.Alternatively, more than one torque-limiting gear may be provided in therotation mechanism.

CONCLUSION

While the position adjusting mechanism, rotation-axle bearing mechanismand rotation-speed reduction mechanism of the invention have beenparticularly shown and described with reference to specific embodimentsthereof, it will be understood to those skilled in the art that variousmodifications or improvements in structure and/or function can be madewithout departing from the spirit or scope of the invention.

INDUSTRIAL APPLICABILITY

In accordance with the position adjusting mechanism of the invention,the positioning of the display screen unit of a stand-type flat displayapparatus equipped with a rotation mechanism can be finely adjusted suchthat the display screen unit can be held horizontally.

In accordance with the rotation-axle bearing mechanism of the invention,a smooth and stable rotation can be obtained in a stand-type flatdisplay apparatus even if the center of gravity of the display screenunit and main body unit of the flat display apparatus is displaced fromthe center of rotation of the stand-rotation mechanism.

Further, in accordance with the rotation-speed reduction mechanism ofthe invention for a stand-type flat display apparatus, the individualcomponents in a stand of the apparatus can be protected from anexcessive or abnormal rotation load during the rotation of the stand.

The flat display apparatus according to the invention can be applied tostand-type flat display apparatuses equipped with a display screen unitsuch as an LCD, plasma or EL display.

Particularly, the invention is suitable for stand-type flat displayapparatuses for business or household purposes equipped with alarge-sized display screen.

1. (canceled)
 2. A flat display apparatus comprising a main body unitwith a display screen and a stand unit with a single rotation axle forsupporting the main body unit, the apparatus further comprising meansfor adjusting the inclination of the horizontal position of the mainbody unit using one eccentric cam and a position adjusting opening wherethe stand unit and the main body unit are connected.
 3. The flat displayapparatus according to claim 2, further comprising means for temporarilysecuring the stand unit and the main body unit and means for fullysecuring the stand unit and the main body unit where the stand unit andthe main body unit are connected, wherein the stand unit and the mainbody unit are temporarily secure to one another and then the inclinationof the main body unit is adjusted by the inclination adjusting means,before the stand unit and the main body unit are fully secured to oneanother.
 4. (canceled)
 5. A flat display apparatus comprising a mainbody unit with a display screen and a stand unit with a single rotationaxle for supporting the main body unit, the apparatus furthercomprising: connecting means for connecting the stand unit and the mainbody unit, wherein the connecting means comprises a securing means forsecuring the stand unit and the main body unit to one another, andinclination adjusting means comprising one eccentric can and a positionadjusting opening for adjusting the inclination of the horizontalposition of the main body unit.
 6. The flat display apparatus accordingto claim 5, wherein the connecting means further comprises a positioningpin for positioning the stand unit and the main body unit.
 7. A flatdisplay apparatus comprising a main body unit with a display screen anda stand unit with a single rotation axle for supporting the main bodyunit, the apparatus further comprising a connecting member forconnecting the stand unit and the main body unit, the connecting membercomprising: a securing opening for allowing the stand unit and the mainbody unit to be secured to one another with a screw; and inclinationadjusting means comprising one eccentric cam and a position adjustingopening for adjusting the inclination of the horizontal position of themain body unit, wherein the inclination adjusting means can adjust theinclination of the main body unit by rotation of the eccentric cam intothe inclination adjusting opening.
 8. A flat display apparatuscomprising a main body unit with a display screen, a stand unit, and arotation mechanism for rotating the main body unit horizontally withrespect to the stand unit, wherein the rotation mechanism comprises aplurality of kinds of bearings for supporting a rotation axle, and thecenter of gravity of the main body unit is located outside a referencerotation periphery defined by the thrust bearing.
 9. The flat displayapparatus according to claim 8, wherein the plurality of kinds ofbearings comprise a combination of a radial bearing and a thrustbearing.
 10. The flat display apparatus according to claim 8, whereinthe plurality of kinds of bearings are mounted towards the top andbottom of the rotation axle.
 11. (canceled)
 12. A flat display apparatuscomprising a rotation mechanism made up of an upper unit and a lowerunit, wherein the lower unit has a single rotation axle secured thereto,and the upper unit has a plurality of kinds of radial bearingssupporting the rotation axle, the upper and lower units being capable ofrotating relative to one another and the center of gravity of the mainbody unit being outside a reference rotation periphery defined by thetrust bearing.
 13. The flat display apparatus according to claim 8,wherein a stopper is disposed near the tip of the rotation axle, thestopper being secured in place while applying a certain force in theaxial direction.
 14. A flat display apparatus comprising a main bodyunit with a display screen, a stand unit, and a rotation mechanism forrotating the main body unit horizontally with respect to the stand unit,wherein the rotation mechanism is adapted to reduce the transmission ofa rotation load upon application of a rotation load exceeding a certainlevel.
 15. (canceled)
 16. The flat display apparatus according to claim14, wherein the rotation mechanism comprises two or more gears, of whichtwo or more gears are torque-limiting gears that are adapted to reducethe transmission of a rotation load upon application of a rotation loadexceeding a certain level.
 17. The flat display apparatus according toclaim 16, wherein the torque-limiting gears include an upper gear and alower gear, wherein the upper and lower gears are adapted to reduce thetransmission of a rotation load by frictionally slide upon one anotherupon application of a rotation load exceeding a certain level.
 18. Theflat display apparatus according to claim 16, wherein thetorque-limiting gears include a gear base, an upper gear secured to thegear base, and a lower gear disposed between the gear base and the uppergear, wherein the gear base has a friction member disposed on thesurface thereof facing the lower gear, and wherein a resilient member isdisposed between the upper and lower gears, the resilient member beingadapted to press the lower gear against the friction member such thatthe lower gear and the gear base frictionally slide upon one another toreduce the transmission of a rotation load.
 19. The flat displayapparatus according to claim 14, wherein the rotation mechanism includesa drive motor and is capable of automatic rotation.
 20. The flat displayapparatus according to claim 19, further comprising means for receivingremote operation, wherein the rotation of the rotation mechanism iscontrolled by remote operation.
 21. The flat display apparatus accordingto claim 14, wherein the rotation mechanism includes a position sensorand is capable of recognizing its own rotation position.
 22. The flatdisplay apparatus according to claim 14, wherein the rotation mechanismis adapted to reduce the speed of rotation between the motor and thegears or between the gears, the rotation mechanism further comprising atorque-limiting gear, wherein the transmission of a rotation load isreduced as an upper gear and a lower gear of the torque-limiting gearfrictionally slide upon one another.
 23. The flat display apparatusaccording to claim 22, wherein the torque-limiting gear includes a gearbase to which the upper gear is secured, and wherein the lower gear isdisposed between the gear base and the upper gear, wherein the gear basehas a friction member disposed on the surface thereof facing the lowergear, and a resilient member is disposed between the upper and lowergears, the resilient member being adapted to press the lower gearagainst the friction member such that the lower gear and the gear basefrictionally slide upon one another to reduce the transmission of arotation load.
 24. The flat display apparatus according to claim 2,wherein the display screen includes a liquid crystal display, a plasmadisplay, or an EL display.